Visual cycle-timer



y 1962 H. T. HODGES VISUAL CYCLE-TIMER Filed May 11, 1959 Howard THodgqs INVENTOR.

United States Patent 3,043,091 VISUAL CYCLE-TIMER Howard T. Hodges, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed May 11, 1959, Ser. No. 812,218 3 Claims. (Cl. 5839.5)

The present invention relates to timers and particularly to a low cost visual cycle timer of the push-button type for timing the cycle of a photographic process.

There are available for timing photographic processes two different types of timers, an electronic timer and a clock driven disk timer.. While the electronic timer is push-button controlled, it is expensive to make and indicates by a light the end of the cycle only and not the progression of time in between. The available clock driven timer runs constantly at one revolution per cycle and the user must remember the random position of the pointer at the beginning of the cycle.

The primary object of the present invention is to provide a low cost timer which provides push-button starting, continuous indications of lapsed time which allows shortcycling, etc., and automatic stop at zero for each subsequent cycle.

Another object is to provide a push-button timer of the type described which has a drive mechanism which prevents jamming of the push-button release no matter how lightly it is actuated.

And a further object is to provide a push-button timer of the type described in which the drive between the clock motor and the timing disk is a slip type drive including a spring which is normally put under tension when the timing disk is stopped and will provide the disk with a quick momentary acceleration the moment it is released to insure that the release latch will be cleared no matter how lightly or quickly it is operated.

The novel features that I can consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its methods of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings in which:

FIG. 1 is a partial front elevational view of a timer constructed in accordance with a preferred embodiment of the present invention;

'FIG. 2 is an exploded perspective view showing the driving and driven components of the timer;

FIG. 3 is a side elevational view, partly in section, and showing the timer parts of FIG. 2 in their assembled relation and behind the wall of a housing therefor which carries the time dial with which th pointer of the timing disk cooperates; and

FIG. 4 is a perspective detail showing another modification of the slip drive between the clock motor and the timing disk.

Referring now to the drawings, a timer constructed in accordance with the present invention consists of a clock motor 10, which in this instance is shown as an electric motor but may be a spring motor, a nylon drive sleeve or pulley 11, a steel hair spring 12, a timing disk 13, a plate 14 having a pointer 15 etched, or otherwise placed thereon, a stud 16, a start push button 17, and a leaf spring 18. As indicated in FIG. 3 the drive pulley 11 threads onto a shaft 19 of the clock motor and is driven at all times. Timing disk 13 and plate 14 are held together by staking of stud 16. The shaft portion of stud 16 is a free fit in a hole 20 in the end of the drive pulley 11. A slip drive connection between pulley 11 and timing disk 13 is provided by the hair spring 12 which has one end wrapped around the groove 23 of the pulley and has its other end extending through a hole in a lug 24 turned out of the disk 13 near its periphery. Thus-the pulley, acting through hair spring 12, provides a low torque moment to the timing disk 13. When not in use, a lug 21 on the end of leaf spring 18 engages a lug 22 formed out of the disk 13 to restrain rotation of the disk assembly, and the looped end of the hair spring 12 slides around in the groove in the drive pulley 11. Thus leaf spring 18 and lug 21 thereon, in cooperation with lug 22 extending from the face of the timing disk 13, provides a releasable spring latch for the disk which can be released by depressing start button 17 carried by leaf spring 18 whereupon the disk assembly is free to turn one revolution. The timer mechanism just described is contained within some sort of housing having a wall 25 provided with a circular opening 26 through which the face of plate 14 is visible, and the edge of which is provided with a dial 27 marked off in increments of time, seconds in this case, with which the pointer 15 cooperates. The start button 17 also extends through a hole 28 in wall 25 to be accessible from the outside of the timer housing. If the timingdisk 13 has the equivalent of lugs 22 and 24 fastened to the face thereof in such a way that the other face of the disk remains intact, then the pointer 15 could be applied directly to this latter face of the disk, making separate plate 14 unnecessary.

Spring 12 serves a second essential function in the slip drive construction. The straight portion, designated at C in FIG. 2, bends slightly when the timing disk assembly is held stationary at the zero position by the latch mechanism. As the start button 17 is depressed to release the latch, the disk assembly, which normally revolves at a very slow speed, jumps forward to free Mg 22 thereon of the latching lug 21. This action avoids a jam when the start button is tapped lightly to start a timing cycle. Without this momentary rapid acceleration of the timing disk assembly upon its being released, it will be appreciated that if start button 17 is not deliberately held depressed for an appreciable time, stop lug 21 might drop back in front of or on top of lug 22 on the timing disk and hold the disk against movement, even if the lugs 21 and 22 are made as thin as possible from the practical standpoint.

In FIG. 4 there is shown another modification of the slip drive between the drive sleeve or pulley 11 and timing disk 13 which has some advantages over the one previously described. In this embodiment the timing disk 13 is connected to the drive pulley 11 by a spring belt 30 which engages the groove 23 in the pulley and has its two free ends'31 attached to the lug 24 extending from the face of the disk 13. In FIG. 4 the slip drive is shown from the side opposite that shown in FIG. 2, and is shown in a latched condition although the leaf spring 18 and its latching lug have been omitted for purposes of clarity. Now assuming that the direction of drive of the pulley 11 and disk 13 is counterclockwise, as shown by arrow 33, and the disk is latched against movement, that the reach of the spring belt toward the direction of drive will be extended or placed under tension, as shown, whereas the other reach of the belt will be relaxed. Thus, as the latch of the timing disk is released upon depression of the start button 17 the tension built up in the extended reach of the belt will immediately momentarily accelerate the timing disk in the direction in which it is normally driven and move it sufliciently to get lug 22 on the disk out of the path of latching lug 21 on leaf spring 18. Consequently, no matter how lightly the release button 17 is tapped in releasing the timing disk, the disk 13 will jump far enough to clear lug 22 from the path of latching lug 21 and prevent an accidental jam up of the parts. This spring belt drive arrangement has the advantage over the hair spring drive embodiment in that a greater driving torque can be transmitted to disk 13 by it. This will permit the timing disk to be used to operate microswitches, or other suitable means during its rotation to provide audible, as well as visible, signals as to when certain points in the cycle are reached should such signalling be desired. The hair spring 12 will not ordinarily provide a sufiicient driving torque to the timing disk 13 so that such added function can be performed by the disk during its rotation.

While I have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be limited to the precise detailed construction shown and described, but is intended to cover all modifications coming within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A cycle timer comprising a clock motor which is normally running; a drive member rotated by said clock motor; a stationary circular dial marked off in increments of time; a rotatable timing disk coaxial with said drive member and including an index cooperating with said stationary circular dial; a releasable latch mechanism for limiting the rotation of said disk to a single revolution and adapted to hold the disk in a start position relative to said dial; and a slip drive connection between said drive member and said disk to allow the drive member to rotate while said disk is held stationary by said latch mechanism and comprising a pulley on said drive member, and a spring member having a portion wrapped around said pulley to frictionally engage the same and having another portion engaged with said disk whereby said spring member will be put under tension when the disk is held stationary and which tension will be relaxed when said latch is released to cause the disk to momentarily quickly accelerate in the direction of drive and prevent re-engagement of said latch regardless of how lightly the latch is actuated to start the cycle.

2. A cycle timer comprising a clock motor which is normally running; a drive pulley rotated by said clock motor; a stationary circular dial marked 01? in increments of time; a rotatable timing disk coaxial with said pulley and including an index cooperating with said stationary circular dial; a stop lug extending from one face of said disk; a releasable spring latch movable from a normal position wherein it engages said lug to stop said disk and hold it in a start position; means for momentarily releasing said latch and allowing it to return to its initial position to limit the rotation of said disk to one revolution; a slip drive connection between said pulley and said disk comprising a hair spring one end of which is wrapped around said pulley and the other end of which is straight and extends substantially radially of said disk and is engaged by said disk adjacent the periphery thereof.

3. A cycle timer according to claim 1, wherein said slip drive connection between said drive member and said disk comprises a spring belt embracing and frictionally engaging said pulley and having the opposite ends thereof fixed to said disk adjacent the periphery thereof.

References Cited in the file of this patent UNITED STATES PATENTS 971,335 Williamson Sept. 27, 1910 988,182 Ewald Mar. 28, 1911 2,253,459 Davis Aug. 19, 1941 2,733,117 Wright Jan. 31, 1956 2,803,300 Warkentien Aug. 20, 1957 2,885,042 Frechette May 5, 1959 

